The present invention concerns a wire locater for use in electrical terminal crimping apparatus of the type in which an electric terminal of generally U-shaped transverse cross section is positioned upon a stationary anvil, an electric conductor is located within the U-shaped terminal, and a crimping die cooperable with the anvil is driven downwardly to fold the upstanding leg portions of the U-shaped portion of the terminal tightly around the conductor to mechanically crimp the terminal into assembled relationship on the end of the conductor. The wire locater of the present invention, while adaptable to other crimping apparatus, is especially designed for use in a crimping apparatus such as that disclosed in my co-pending application Ser. No. 06/690,256, filed Jan. 10, 1985, now U.S. Pat. No. 4,598,570.
In the apparatus disclosed in my aforementioned application, electric terminals to be crimped are fed in step-by-step movement to the apparatus integrally attached at one end to an elongate carrier strip, each step of movement of the carrier strip advancing a terminal into position upon a stationary anvil of the crimping apparatus. The anvil is formed with a flat front surface lying in a general vertical plane and a vertically movable cutter element slides in face-to-face engagement with the front surface of the anvil. The face of the cutter engaged with the anvil is formed with a horizontal slot which slidably receives the carrier strip to properly locate the terminal relative to the anvil and, in a normally maintained rest position, to guide the terminal onto the upper surface of the anvil. A vertically movable die assembly is mounted above the anvil and a terminal is advanced to the anvil by driving the carrier strip forwardly while the die assembly is in a raised position. When the terminal is located on the anvil, a wire is moved into alignment with the terminal and the die assembly is driven downwardly to perform the crimping operation. During this downward movement of the die assembly, the die assembly engages the cutter and drives the cutter downwardly. The carrier strip is trapped within the horizontal slot in the cutter, and upon downward movement of the cutter the terminal on the anvil is sheared from the carrier strip along the plane of engagement between the cutter and the vertical front face of the anvil. The die assembly is then raised and the cycle is repeated.
In order to produce a satisfactory mechanical and electrical connection between the wire and the terminal, the wire end which is to be crimped to the terminal must be moved into vertical alignment with the U-shaped portion of the terminal so that the wire is centered between the opposed legs of the U-shaped section immediately prior to the crimping of the legs onto the wire. Various wire locating devices for performing this function are known in the prior art. In general, many of the prior art devices have been found satisfactory for use with larger wire sizes where the wire and its insulation are reasonably rigid. However, the trend toward miniaturization of electric circuitry and circuit elements has resulted in the usage of increasingly smaller terminals and relatively small or fine wires. The reduction in size of the terminal itself increases the degree of precision required to accurately align the wire and terminal, while at the same time the finer wires employed with the smaller terminals are very flexible and easily bent.
With the smaller terminals, feeding of the terminals by means of a carrier strip as described above is almost the universal practice and usage of the carrier strip feeding method requires that the terminal be sheared from the carrier strip as it is crimped upon the wire. Because feeding the wire into position with respect to the terminal finds the wire passing across the top of the cutter, prior art wire locaters have been located at the side of the cutter remote from the terminal. Because a portion of the vertically movable die assembly conventionally engages the top of the cutter to drive it downwardly in shearing movement, apparatus for locating the wire relative to the terminal must be clear of the path of movement of the die assembly and thus, of necessity, spaced some distance (one-half inch or more) from the terminal. Where the wire is sufficiently rigid, this spacing does not pose any great problem; but when extremely fine wire is used, the end of the wire beyond the locater may be bent within this spacing to a degree where it may entirely miss the terminal.
The present invention is directed to the provision of a wire locater assembly for use in crimping apparatus of the type referred to above in which the wire may be gripped by the locater closely adjacent the front vertical surface of the anvil so that the only portion of the wire not supported by the locater is that which vertically overlies the terminal.